1: Biochemistry  1978 Nov 14;17(23):5026-31 

Effect of cholesterol on the molecular motion in the hydrocarbon region of
lecithin bilayers studied by nanosecond fluorescence techniques.

Kawato S, Kinosita K Jr, Ikegami A.

Effects of cholesterol on the dynamic structure of the hydrocarbon region of
dipalmitoyllecithin vesicles were examined. Decays of the emission anisotropy
and the fluorescence intensity of 1,6-diphenyl-1,3,5-hexatriene embedded in
lecithin-cholesterol vesicles were measured over a temperature range of 10--60
degrees C. The emission anisotropy decreased rapidly with time and then leveled
off. The rotational motion of the probe was analyzed by a model of wobbling
diffusion confined in a cone. Cholesterol (10--50 mol%) decreased the cone angle
in the liquid-crystalline phase and increased it in the gel phase. In the
presence of 33 mol% cholesterol, the wobbling diffusion constant increased in
the gel phase and changed little in the liquid-crystalline phase. The viscosity
in the cone decreased in the gel phase and remained almost unchanged in the
liquid-crystalline phase in the presence of 33 mol% cholesterol. The total
fluorescence intensity followed a singel exponential decay independently of the
cholesterol content 0--50 mol%.

PMID: 718871 [PubMed - indexed for MEDLINE]